Doll-head bearing for drying cylinders



March 10, 1931.

w. PTEVANS 1,795,546

DOLL HEAD BEARING FOR DRYING CYLINDERS Filed Nov. 9 1929 2 Sheets-Sheet1 Q 1) 3 g d C N A2 a A c I A 1 a 131 By @AW HTTORNEV March 10, 1931.w,-p EVANS 1,795,546

DOLL HEAD BEARING FOR DRYING CYLINDERS Filed Nov. 9. 1929 2 SheetsSheet2 4 2 A1 A s E 411) A? T v if u i i mvnvrop $00M Patented Mar. 10, 1931PATENT OFFICE WILLIAM PARSONAG-E EVANS, OF SWIN'ION, ENGLAND DOLL-HEADBEARING FOR DRYING CYLINDERS Application filed November 9, 1929, SerialNo. 406,142, and in Great Britain. November 26, 1928'.

This invention relates to improvements in the bearings for the trunnionsor hollow shafts of steam heated revolving cylinders used in machinesfor. drying textile fabrics U and paper such as are known as doll headbearings.

Owing to theexpansion of .such cylinders it isnec'essary to provide ayielding joint between thefixed pipe supplying the steam to the cylinderand it 1s also necessary to provide means whereby the joint will bebroken when the supply of steam is cut off to prevent the formation of apartial vacuum in the cylinder. Joints for'this purpose are alreadyknown in 1 5 which the closure device-bearing against the end of thehollow trunnion is carried at the centre of a flexible diaphragm rigidlyheld around its periphery, the action of the steam pressure on thediaphragm being such that 10 it moves at the centre towards the cylindertrunnion and holds the closure device tightly against the end thereof.When the supply of steam iscut off however the contraction of thecylinder causes the end of the trunnions to move away from the closuredevice and opens the inside of the cylinder to the atmosphere therebypreventing the formation ofa partial vacuum within the cylinder.Accordingto the present invention the diaphragm is anchored at thecentre to a hollow support separate frombut aflixed to the doll headcasting through which the steam passes and is attached at its peripheryto the closure device which can move relatively to the fixed support,the closuremember being of such shape that a hollow steam chamber isformed between its inner surface and the diaphragm. V

By this arrangement the whole of the closure member is entirely freefrom thefixed doll head casting and the steam in the steam chamber sinceit acts in one direction in the diaphragm and in the opposite directionon the inner face of the closure member maintains the whole in a stateof equilibrium. The area of the diaphragm on which the steam acts may beless than the area of the closure member so that the difference betweenthese two areas forms the effective area for makingthe joint thusbringing about a closure without causing a great amount of frictionbetween the closure member and the end of the trunnion and so reducingthe wear between the closure member and the end of the revolvingtrunnion. If desired a spring or a number of springs arrangedcircumferentiallymay be employed to keep the closure member normallyagainst the end of the trunnion and the steam pressure acting on theeffective area cause the face of the closure 00 member to'make a steamtight jointwith the end of the trunnion.

Instead of the area of the diaphragm being less than the area of theclosure member it could be equal thereto or greater than the 5 area ofthe closure member. In the former case the steam in the chamber wouldkeep the closure member in equilibrium and in the latter would tend tomove the member away from the cylinder end. In both cases the steamtight joint between the closure member and the end of the cylinder shaftwould be maintained by the pressure of the spring.

The invention will be described with reference to the accompanyingdrawings Fig. 1 is a transverse section through one form of theinvention.

Fig. 2 is a section on line 22 Fig. 1.

F ig. 3 is a transverse section through anotherform of the invention.

Fig. 4 is a transverse section through a modification of the inventionhaving two'diaphragms.

Fig. 5 is a transverse section through the bearing of a paper dryingcylinder. 35

In the form of the invention shown in Figs.

1 and-2 an elbow casting A having a steam passage a is mounted on top ofthe doll head casting B. A screwed sleeveA is screwed into the outletend of the steam passage a and an annular diaphragm C is clamped betweenthe flanged end of the sleeve A and the end of the casting A. Theclosure member D D is aifixed bybolts d to the diaphragm G near theperiphery thereof. The closure member D is formed in two parts D, Daifixed together by-the bolts (Z with a chamber D between them, intowhich chamber steam from the passage a can enter. The part D has apassage d for steam to enter the hollow shaft E and is formed with amachined face (l1 which bears against the end of the shaft E to make asteam tight joint therewith. The other member D has an extending flanged surrounding the elbow casting A and forming a housing for a spring Awhich bears at one end against the member D and at the other against thecasting A. The whole of the closure member D D is thus entirelysupported at the periphery of the diaphragm C and can move relatively tothe casting A so that the face al can be pressed up against the end ofthe shaft E.

The inner diameter of the annular diaphragm C is greater than the boreof the passage (Z through which the steam passes to the shaft E so thatthe area of the member D acted on by the pressure of the steam in thechamber D is greater than the area of the diaphragm C acted on by thesteam pressure. Since the pressure of the steam tends to move the memberD towards the shaft E and to move the diaphragm C in the oppositedirection the diflerence between these two areas is the effective areathe pressure on which forces the face d of the closure member againstthe end of the shaft.

Although the spring A might be omitted and the pressure on the effectivearea be employed alone for making the joint it is preferred to employthe spring A which is of sufficient strength to hold the face (Z of theclosure member against the end of the shaft and to employ the pressureon the effective area to ensure a tight joint between the face (Z andthe shaft without causing a great amount of friction as the shaftrotates.

The elbow casting A is formed with a flange a which is bolted to aflange on the doll head B so that the closure member D D and the castingA. can be readily removed from the doll head bearing for the purpose ofreplacement or repair.

In the form of the invention shown in Fig. 3 the construction of theclosure member 13 ,13 is the same as that described with reference toFigs. 1 and 2. The diaphragm C is clamped at the centre between thescrewed sleeve A and a tube F which is screwed into the doll head B andlocked in position by the nut Thus by slacking off the nut f the tube Fand closure member I), D can be removed from the doll head or adjustedrelatively to the end of the shaft E.

5 shows the invention applied to the doll head bearing of a paper dryingmachine. The construction of the closure members D D is similar to thatdescribed with reference to Fig. 1. The bearing face (Z however bearsagainst a shoulder e on the shaft E instead of against the end thereof.The sleeve A clamping the diaphragm C at the centre is screwed into asleeve A surrounding the shaft E and bolted to the doll head casting B.

In the arrangement shown in Fig. ti: the

two members D D of the closure device are separated by aring d and asecond annular diaphragm C is clamped between the memher I) and the ring(P. A ring d is affixed to the second annular diaphragm C and the faceoil of this ring makes contact with the end of the shaft E. The innerdiameter of the diaphragm C is less than that of the diaphragm C so thatthe effective area acted on. by the steam to hold the ring d" againstthe end of the cylinder is the difference between the areas of the twodiaphragn'is. The diaphragm C is clamped at the centre to an elbowcasting k as described with reference to Fig. 1. A spring A presses themember D against the diaphragm C to keep it pressed forward towards theend of the shaft E.

Although in the drawings the area of the closure member ID is shown anddescribed as being larger than the area of the diaphragm C its area maybe equal to or less than that of the diaphragm in which cases the steamtight joint between the closure member and the end of the cylinder shaftwould be maintained by the pressure of the spring and in the latter casethe steam pressure would tend to move the closure member away from thecylinder end.

The closure member maybe provided with a readily detachable seatingeither of metal or fibrous material to make a steam tight joint. Theseating may be spherical or flat and may have a different diameter ofbore to the passage through the shaft E to suit or balance various steampressures.

If desired two or more of the diaphragms may be arranged one behind theother each diaphragm being carried on a central tube supported from thepreceding diaphragms.

Where two doll heads are employed one at either end of a drying cylinderthe one may be constructed so that the steam will assist to force theclosure member against the end of the cylinder and the other to move itaway from the cylinder end.

VJ hat I claim as my invention and desire to protect by Letters Patentis 1. In a doll head bearing for the trunnion of a steam heated cylinderthe combination with the closure member forming a steam tight joint withthe end of the shaft of a non-rotating diaphragm to the periphery ofwhich the closure member is affixed, and a central support independentof but affixed to the doll head casting to which the diaphragm isanchored at its centre.

2. In a doll head bearing for the trunnion of a steam heated cylinderthe combination with the closure member forming a. steam tight jointwith the end of the shaft of a nonrotating diaphragm to the periphery ofwhich the closure member is affixed, a central hollow sleeve aiiixed tothe doll head casting to which the diaphragm is anchored at its centreand a spring to assist the pressure of the steam in keeping the closuremember against the end of the shaft.

3. In a doll head bearing for the trunnion of a steam heated cylinderthe combination with the closure member forming a steam tight oint Withthe end of the shaft of a nonrotating diaphragm, a central supportindependent of but aflixed to the doll head casting to which thediaphragm is anchored at its centre, a second diaphragm afiixed at itsperiphery to the first diaphragm and carrying the closure member at itscentre.

In testimony whereof I have hereunto set my hand.

WILLIAM PARSONAGE EVANS.

